本文選題：活性粉末混凝土 + 粘結應力-滑移本構模型　； 參考：《北京交通大學》2013年博士論文

【摘要】：摘要：活性粉末混凝土是一種具有超高強度、高韌性、高耐久性、高環(huán)保性的新型水泥基復合材料,在土木工程領域具有廣闊的應用前景。工程中活性粉末混凝土構件多以配筋的形式出現(xiàn),為研究鋼筋與活性粉末混凝土之間的協(xié)同作用機理,本文通過梁式試驗、中心拔出試驗、鋼筋內(nèi)貼片試驗對變形鋼筋與活性粉末混凝土之間的粘結性能進行了研究。分析了變形鋼筋在活性粉末混凝土構件中的粘結錨固機理和粘結錨固強度變化規(guī)律,以解決活性粉末混凝土構件中鋼筋的錨固設計問題,為活性粉末混凝土規(guī)范的編制提供依據(jù)。論文主要工作和結論如下： (1)進行了一批活性粉末混凝土梁式粘結試驗,通過改變活性粉末混凝土內(nèi)鋼纖維體積摻量、保護層厚度、粘結長度等因素,分析了各因素對試件破壞形式、粘結應力-滑移曲線、粘結錨固特征值的影響。研究表明：錨固條件對鋼筋與活性粉末混凝土之間的粘結性能具有很大影響并對試驗結果進行統(tǒng)計回歸,得出了變形鋼筋與活性粉末混凝土之間的粘結錨固強度和滑移的計算公式； (2)通過梁式試驗和中心拔出試驗對鋼纖維體積摻量為0.0%～2.0%的活性粉末混凝土與鋼筋之間的粘結性能進行了研究,對比分析了不同試驗方法下粘結強度隨鋼纖維體積摻量變化規(guī)律。同時進行了一組C40混凝土梁式試驗,與鋼纖維體積摻量為2.0%的活性粉末混凝土試件進行對比,研究變形鋼筋在不同混凝土基體中粘結性能差異,并從微觀結構方面分析了活性粉末混凝土的粘結錨固機理。研究表明：兩種試驗方法下得到的粘結強度都隨鋼纖維體積摻量的增加而增大,但梁式試驗的粘結強度增長趨勢大于中心拔出試驗,鋼纖維體積摻量為0.0%時,中心拔出試驗的粘結強度大于梁式試驗；鋼纖維體積摻量為0.5%-2.0%時,中心拔出試驗的粘結強度小于梁式試驗；變形鋼筋與活性粉末混凝土之間的粘結強度要遠大于C40混凝土；活性粉末混凝土致密的結構及鋼纖維的摻入是其具有超高粘結強度的原因； (3)進行了鋼筋內(nèi)貼片試驗,根據(jù)實測鋼筋應變,分析了不同位置處粘結應力變化規(guī)律,研究粘結長度內(nèi)變形鋼筋在活性粉末混凝土中的粘結應力分布規(guī)律,推導出了反映這種變化的位置函數(shù)；根據(jù)試驗結果推導的粘結錨固特征值將粘結應力-滑移曲線分段,建立了考慮粘結位置的粘結應力-滑移本構模型； (4)在上述試驗基礎上,通過錨固可靠度分析及現(xiàn)有規(guī)范對鋼纖維體積摻量為0.0%～2.0%的活性粉末混凝土中變形鋼筋的粘結長度提出了實用設計建議,為制定相關規(guī)范提供了依據(jù)。
[Abstract]:Abstract: reactive powder concrete (RPC) is a kind of new cement matrix composite with super high strength, high toughness, high durability and high environmental protection. It has a broad application prospect in civil engineering field. In order to study the mechanism of synergistic action between rebar and reactive powder concrete, the beam test and central pull-out test are carried out in this paper. The bonding behavior between deformed steel bar and reactive powder concrete (RPC) was studied by internal patch test. The mechanism of bond anchoring of deformed steel bars in reactive powder concrete (RPC) members and the variation law of bond anchoring strength are analyzed in order to solve the problem of anchoring design of rebar in reactive powder concrete (RPC) members. To provide the basis for the preparation of reactive powder concrete code. The main work and conclusions are as follows: 1) A batch of beam-type bond tests of reactive powder concrete (RPC) were carried out. By changing the volume content of steel fiber, the thickness of protective layer and the bond length, the failure modes of the specimens were analyzed by changing the volume content of steel fibers, the thickness of the protective layer and the bond length of the RPC. The bond stress-slip curve and the effect of bond anchoring eigenvalue. The results show that the anchoring conditions have a great influence on the bond properties between rebar and reactive powder concrete (RPC) and the test results are statistically regressed. The formula of bond Anchorage strength and slip between deformed steel bar and reactive powder concrete is obtained. 2) through beam test and central pull-out test, the bond behavior between reactive powder concrete (RPC) with 2.0% steel fiber volume and steel fiber volume is studied, and the change of bond strength with steel fiber volume content under different test methods is compared and analyzed. At the same time, a group of C40 concrete beam tests were carried out, which were compared with the reactive powder concrete specimens containing 2.0% steel fiber volume. The difference of bond behavior of deformed steel bars in different concrete matrix was studied. The bonding and anchoring mechanism of reactive powder concrete is analyzed from microstructure. The results show that the bond strength of the two test methods increases with the increase of the volume content of steel fiber, but the increasing trend of bond strength of beam test is larger than that of central pull-out test, and when the volume content of steel fiber is 0.010, the bond strength of beam test is larger than that of central pull-out test. The bond strength of the central pull-out test is greater than that of the beam test, the bond strength of the central pull-out test is smaller than that of the beam test when the volume content of steel fiber is 0.5- 2.0%, the bond strength between the deformed steel bar and the reactive powder concrete is much higher than that of the C40 concrete. The dense structure of reactive powder concrete and the incorporation of steel fiber are the reasons for its super high bond strength. According to the measured strain of steel bar, the variation law of bond stress at different positions is analyzed, and the distribution of bond stress of deformed steel bar in reactive powder concrete (RPC) in bond length is studied. The position function reflecting this change is derived, and the bond stress-slip curve is segmented according to the eigenvalue of bond anchoring derived from the test results, and the bond stress-slip constitutive model considering the bond position is established. 4) on the basis of the above tests, through the Anchorage reliability analysis and the existing codes, the paper puts forward some practical design suggestions for the bond length of deformed steel bar in the reactive powder concrete (RPC) with the volume content of steel fiber as 0.00%, which provides the basis for the formulation of relevant codes.
【學位授予單位】：北京交通大學
【學位級別】：博士
【學位授予年份】：2013
【分類號】：TU528

【參考文獻】

相關期刊論文 前10條

1 張明波;閻貴平;閆光杰;安明U，

本文編號：1818264